1.) Field of the Invention
This invention relates to a modular printer. The invention relates particularly, but not necessarily exclusively, to a modular commercial printer for effecting high speed, digital, photographic quality, commercial printing. The invention relates specifically to a print engine for a modular commercial printer.
2.) Background to the Invention
In high-speed printing, large printing presses are daisy-chained together to print predetermined pages of publications, which are then secured together to form the publications. Such printing presses occupy an extremely large volume and are very expensive.
The applicant has also proposed a commercial printer using a number of floor-mounted printers having pagewidth print heads. This commercial printer is intended for extremely high production rates such as up to five 180-page documents per second.
To achieve such high production rates, large quantities of consumables need to be readily available for the printers. Thus, once again, such a commercial printer needs to occupy an extremely large volume although the cost of such a printer is considerably lower than equivalent high end, commercial printers which do not use the applicant""s Memjet (Memjet is a trade mark of Silverbrook Research Pty Ltd) technology.
The applicant has recognised a need for a commercial printer which occupies a smaller volume and which has a lower throughput rate but of the same quality as the applicant""s previously proposed Memjet commercial printer.
According to the invention, there is provided a print engine for a printer, the print engine comprising
a support structure;
a pair of drive rollers that are rotatably mounted on the support structure and are configured to define a gripping zone into which a sheet of print medium can be fed to be gripped between the rollers, the drive rollers defining a feed zone between the gripping zone and a tangential plane common to both drive rollers through which the sheet of print medium passes; and
at least one print head assembly that comprises
at least one print head chip carrier that is mounted on the support structure and which is configured to extend into the feed zone; and
at least one print head chip that is mounted on each print head carrier to be in an operative position with respect to the sheet of print medium in the feed zone.
The print engine may include at least one pair of substantially identical print head assemblies, the at least one print head chip carrier of one print head assembly being mirrored by the at least one print head chip carrier of another print head assembly so that the print head chips can be operatively positioned with respect to both sides of the sheet of print medium.
Each print head assembly may include two substantially identical print head chip carriers so that a first pair of carriers is mirrored by a second pair of carriers and the print head assemblies together define a distal pair of mirrored carriers and a proximal pair of mirrored carriers relative to the gripping zone, at least the print head chips mounted on the proximal pair of carriers being positioned in the feed zone.
The at least one print head chip carrier may have an arcuate end profile that corresponds generally with the curvature of a periphery of each drive roller.
The invention extends to a printer that includes at least one print engine as described above.
Each print head chip carrier may include a molding. Each molding preferably defines a plurality of galleries for supplying different inks to its associated print head chip. In this specification the term xe2x80x9cinkxe2x80x9d is to be understood in a broad sense as including visible inks of various colors, an ink which is invisible in the visible spectrum but is visible in the infrared spectrum, a fixative for fixing the ink on the print media and a varnish for coating printed matter on the print media.
Each molding may include an air channel for feeding filtered air to the print chips for inhibiting the build up of debris and foreign matter on the print chips.
The assembly may include a control means for controlling operation of the, or each print head chip, said control means being mounted on said at least one molding and communicating with said print head chip via a connector. The connector may be a flexible PCB wrapped about a part of a periphery of said at least one molding. In the case where two moldings are provided, each molding may have a flex PCB associated therewith wrapped about a part of its periphery. Preferably, the flex PCB is wrapped about a convex part of a periphery of each molding.
It will be appreciated that, by having each molding substantially scythe shaped, when view end-on, the print head chips of the moldings are brought into close proximity to a rotational axis of the feed means thereby enabling a closely controlled print media to print head gap to be maintained.